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helgehelge123andhelgehelge123
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Every protected request spawns a fresh helper subprocess, paying interpreter start and imports before any work begins. Measured inside the container, five consecutive runs of `python -c "import shelfmark.bypass.internal_bypasser"`: ``` 3.53s 3.45s 3.55s 3.54s 3.46s ``` A single search issues several protected requests, so that is paid several times over per search. ## What changed The helper now serves one JSON request per line of stdin until the parent closes the pipe, and an idle timer (`BYPASS_BROWSER_IDLE_TIMEOUT`, default 180s) shuts it down once searching stops. Answers still travel by result file, but the file is now written to a `.part` path and renamed into place — the parent treats the file's existence as the answer, so it must never observe a half-written one. stdout and stderr stay attached to the parent's, so helper logs keep appearing in `docker logs` exactly as before. Failure handling, since a warm helper is exposed to more of it than a per-request one ever was: | Situation | Handling | | --- | --- | | Helper died between requests | Detected via `poll()`, respawned | | Pipe broken at write time (`poll()` can miss this) | One retry on a fresh process; a fresh one failing there is a real failure | | Helper exits without writing a result | `RuntimeError` naming the exit code | | Wedged past the timeout, or cancelled mid-bypass | Helper killed, then `_cleanup_orphan_processes` because a killed helper never got to close Chrome | | Idle reaper racing an arriving request | Re-checks the deadline under the lock and re-arms instead of killing a helper that just did work | The DNS config now travels with every request rather than only at spawn: a warm helper outlives changes the parent makes to its provider. ## `BYPASS_REUSE_BROWSER`, off by default This parks the CDP driver between bypasses. A driver's websockets are bound to the loop that opened them and cannot outlive their process, so the persistent helper is what makes this possible at all — and the warm path runs on `_CDP_WORKER`'s long-lived loop rather than `asyncio.run` for the same reason. The mechanism works. With it on, the browser start disappears from the second request onward: 0.7s from `Reusing warm Chrome browser` to the first bypass attempt, against roughly 16s cold. **It still ships off, because a matched-pair test shows it is a net loss against DDoS-Guard.** Each round primed with one cold bypass, waited 10s, then measured a second — identical timing in both arms, only the browser strategy differing, order balanced (fresh, warm, warm, fresh) so drift over the session cannot masquerade as an effect: | Arm | Measured request | | --- | --- | | fresh browser | 42.8s, 40.6s | | warm browser | 57.1s, 59.6s | Spread within each arm is 2.2s and 2.5s, against 16.7s between them. Reuse removes the ~15s browser start and then gives back roughly twice that in solving: a returning browser draws a harder challenge. Where the cold browser is through on the second bypass method, the warm one fails the first three and only `_bypass_method_humanlike` gets it, at ~30s for that method alone. Worth separating from a second effect I ran into while measuring: five back-to-back searches slow from ~32s to 51–98s with reuse **disabled** as well, so DDoS-Guard escalates on request rate independently of any of this. That is why the pairs above are timed identically rather than simply run in sequence. It is the larger of the two effects, but not something this project can patch around. Reuse is left available rather than dropped because Cloudflare sites may not respond the same way, and because the two concerns are independent: the helper start is pure overhead and always worth removing, the browser is not. ## Verification - 2559 unit tests pass (2542 before, 17 added in `tests/bypass/test_warm_browser.py`) - `ruff check`, `ruff format`, `basedpyright` over backend and tests, and `vulture` all clean - `docs/environment-variables.md` regenerated via `scripts/generate_env_docs.py` - Live against Anna's Archive on a warm helper: searches return their usual ~760KB and 667 results, the app's own search warm-up completes with 50 results, and the container is left with no orphan chrome/Xvfb/ffmpeg processes Happy to drop the `BYPASS_REUSE_BROWSER` half entirely if you would rather not carry a default-off path — the helper persistence stands on its own. Co-authored-by: helgehelge123 <helge.neumann@zollsoft.de>